public class Solution1 {
    //1137. 第 N 个泰波那契数
    public int tribonacci(int n) {
        if (n == 0) {
            return 0;
        } else if (n == 1 || n == 2) {
            return 1;
        }
        int[] dp = new int[n+1];
        dp[0] = 0;
        dp[1] = 1;
        dp[2] = 1;
        for (int i = 3; i < n+1; i++) {
            dp[i] = dp[i-1] + dp[i-2] +dp[i-3];
        }
        return dp[n];
    }
}
